'Canary in a coal mine': Scientists test alligators for PFAS chemical compounds

In new studies on wildlife, researchers have found evidence that exposure to per- and polyfluoroalkyl substances, or PFAS, could harm an animal's immune system.

Alligators in the lower Cape Fear River had changes in their immune system that could indicate the development of autoimmune-like diseases in response to exposure to high-levels of the contaminants, according to information presented at a forum Tuesday related to the PFAS compound.

The PFAS family of chemicals has been used in products for decades. The compounds have been used to make cookware, food packaging, stain repellents and other products.

The PFAS group of chemicals includes GenX, which is manufactured by the Chemours company at its Bladen County plant. GenX has been connected to cancer and other diseases in animal studies, but it isn’t known if the effect is the same on humans.

At the event hosted by the NC Policy Collaborative and the NC PFAS Testing Network, researchers presented new information about PFAS chemicals in animals and soil. 

'Canary in a coal mine'

Last year, in a report released by N.C. State University, researchers found elevated levels of PFAS chemicals in the blood of Cape Fear River striped bass. The chemicals had an adverse affect on the immune and liver functions in the fish.

Scott Belcher, a research professor in toxicology at N.C. State, spearheaded the research to study PFAS exposure and what affect the chemicals had in fish and alligators in the Cape Fear watershed in 2018.

He presented new findings related to alligators at the forum Tuesday.

"Our study goals were then just to use these guys as kind of that proverbial 'canary in a coal mine,' to really look and see what kind of predictive affects we might be able to see in these animals that have had these chronic exposures," Belcher said.

More:  Have we been eating potentially dangerous compounds in our food for years?

In testing of one population of alligators in the watershed, the health impacts were alarming, Belcher said. The team of researchers compared the animals living on the golf courses in proximity to the Cape Fear to the ones living in the river. 

The alligators that were tested were in Lake Waccamaw and in the Cape Fear. 

The researchers found markers of lupus-like immunity in the reptiles, as well as skin lesions and slow healing wounds.

Belcher said this was very rare in reptiles from other sites.

"Alligators are known to heal very, very quickly. Typically we've seen multiple alligators that have lost a leg to another alligator and those can heal up in a matter of weeks," Belcher said. "But we saw these very atypical lesion wounds."

Belcher said with this evidence, the team is building a case highlighting the immune differences in the animals that result in auto-immune diseases. 

"The alligators, they're actually a really nice species for these types of exposures because they typically don't move very far," Belcher said. "We were looking at exposures trying to define how many different PFAS we could see in their blood and then looking at this question of bioaccumulation and bioconcentration, and impacts on their health."

More research will be conducted from these findings on the alligators to determine the extent of the chemicals' affects.

"We're now doing annual monitoring of alligators and fish," Belcher said.

More research is needed

Owen Duckworth, a soil and environmental biogeochemistry professor at NC State, presented updates at the forum on testing of chemicals in soil that produces crops people eat. He said researchers are trying to determine if contamination in soil can be transported into the edible parts of plants. 

"We know that people are drinking water that has PFAS in it, or have been in the past," he said. "Are they also eating crops or food they grow that has it in it?"

Duckworth said that even though testing is being done to find chemicals in the soil growing crops, more research needs to be done to determine if people are eating produce contaminated with PFAS and if they are eating it at levels that pose threats to their health.

People with contaminated private wells might have contaminated soil, but there is not an easy way to tell, Duckworth said. 

"There are a lot of different PFAS compounds, we don't know specifically which of these are harmful," he said. 

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Regional Enterprise Reporter Kristen Johnson can be reached at kjohnson1@gannett.com or 910-486-3570.